The present technology generally relates to a battery module and a battery device using, for example, a lithium ion secondary battery.
A battery module in which a plurality of unit cells (also referred to as battery cells) are connected in series is known. As a unit cell, for example, a lithium ion secondary battery is used. Furthermore, if the battery modules can be connected in series, the output voltage can be increased.
The battery module is one which outputs a predetermined DC voltage. In the configuration in which a voltage of the battery part formed by connecting the unit cells in series always appears at an output terminal, since there is a danger of electric shock or short circuit, a load switch is inserted between the battery part and the output terminal. When a mechanical switch such as a relay or a tact switch is used as a load switch, reliability concerns such as contact deterioration and mechanical failure are present. For this reason, an FET (Field Effect Transistor) is used as a load switch.